Electric-arc lamp



(No Model.) 2 Sheets-Sheet 1.

S. W. RUSHMORE.

ELECTRIC ARC LAMP.

No. 472,274. Patented Apr. 5, 1892.

lmi mwaeo 5440014 606 gr m m. 1.14 Z-M M (No Model.) 2 Sheets-Sheet 2.

S. W. RUSHMORE.

ELBGTRIG ARG LAMP.

No. 472,274. Patented Apr. 5, 1892.

m: Noam: puns 20., mow-Lima, WASNNGTGN, u. c.

UNITED STATES PATENT OFFICE.

SAMUEL V. RUSHMORE, OF BROOKLYN, NEXV YORK.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 472,274, dated April 5,1892. Application filed July 27, 1891. Serial No. 400,808. (No model.)

To aZZ whom it may concern.-

Be it known that I, SAMUEL W. RUsHMoRE, a citizen of the United States,residing at Brooklyn, in the county of Kings and State of New York, haveinvented a certain new and useful Improvement in Are Lamps, of which thefollowing is a specification.

The present invention relates to mechanism for advancing the movablecarbons of arc lamps.

The main object isto providea lamp adapted for use on aconstant-potential circuit such as the usual incandescent circuitsinwhich the feeding of the carbon shall not depend entirely on thestrength of a shunt coil or magnet, but shall depend, also, on theoperation of a coil or magnet in series with the are, as hereinaftermore full ysetforth and claimed.

In the accompanying drawings, Figure 1 is a perspective. view of themain parts of an arc lamp, showing the improvement applied thereto. Fig.2 shows a side view of the clutches and parts connected thereto.

1 is the movable carbon or the movable rod which carries the carbon inthe usual manher, and 2 is the lower and preferably stationary carbon.

3 is the positive terminal of the lamp, and is connected to the coarseseries coil 45, the opposite end of which is connected by conductor 5 tothe lower carbon. In the lamp as constructed this conductor will be oneof the side rods of the frame.

6 is the negative terminal of the lamp.

7 is a high-resistance shunt-coil connected between the terminal 6 andthe conductor 5. Instead of being connected directly to the terminal 6or to the frame of the lamp, the shunt-coil is connected to a spring 6,which normally rests against the carbon-carrying rod, and is thusconnected to the frame and terminal 6. With this arrangement when thecarbon is fed down until it is all consumed, the upper end of thecarbon-rod will leave the spring 6 and open the circuit through theshunt-coil. Were it not for this the entire potential of the systemwould be left on the shunt-coils, subjecting them to the danger ofburning out.

8 is the armature of said coil, and is provided with a spring 9 or othersuitable retractor. To the armature is pivoted a link 10, the lower endof which is pivoted to a Y- shaped lever 11, the two branches of whichare pivoted to the two posts 12. Above this lever is a clutch plate orring 13, surrounding the carbon or carbon-carrying rod and having anextension or arm 14: on one side, at the end of which is a link 15,formingamech'anical connection between the lever 11 and the clutch. Atthe opposite side the clutch plate or ring has an arm 16, which standsover a post 17 and is adapted to strike said post when moved.

18 is the armature of the series coil, and is connected by a link 19 toa Y-shaped lever 20, also pivoted to the two posts 12. Below this leveris a second clutch-plate 21, surrounding the carbon or carbon-carryingrod and having an arm 22 connected by link 23 to the lever 20. Theclutch controlled by the shuntcoil is so arranged that it grips andholds the carbon when the armature of said coil is in its retractedposition, while the clutch of the series coil is so arranged that itgrips and holds the carbon when the armature of that coil is in itsoppositethat is, its attracte(l-position.

24. is a dash-pot, serving to retard the movement of the armature 18.

XVhen the circuit is first closed to this lamp, the shunt-coil isimmediately energized and attracts its armature, causing the clutch 13to release its grip on the carbon and allowing the carbon to fall untilit comes in contact with the lower carbon. This immediatelyshort-circuits the shunt-coil, the circuit being from the insulatedbinding-post 3, through the series coil, conductor 5, carbons, to theframe of the lamp, and to the binding-postG, in metallic connection withthe said frame, and the armature 8 is retracted by the spring 9 raisingthe carbon and establishing the arc. The circuit when first closedincludes the series coil; but the armature thereof is not influenced bythe small current passing the shunt, but is attracted by the maincurrent after the arc is established. When the carbon is entirelyconsumed, the end of the rod comes below the spring 6', thereby openingthe circuit of the shunt-coil and protecting it from injury, as alreadydescribed.

When several of the lamps are placed in series on a clrcuit of constantpotential, they will burn regularly and practically together, thusobviating one of the serious diificulties which has existed in operatingarc lamps on incandescent circuits.

What I claim is- 1. The combination, in an arc lamp, of a movable carbonor carbon-carrying rod, a shunt-coil, a clutch ring or plate controlledthereby, a series coil, and a separate feeding device controlledthereby, one of said devices acting as a check on the other,substantially as described.

2. The combination, in an arc lamp, of carbons, means for holding thesame apart when the lamp is out of use, a shunt-coil and armaturetherefor, the latter being connected to said means in such manner as tocause the movable carbon to advance when the armature is attracted, aretractor for the armature acting against the shunt-coil, a series coil,an armature therefor, and means operated thereby for holding the carbonwhen the armature of the series coil is attracted, substantially asdescribed.

3. The combination, in an arc lamp, of carbons, a clutch for holding thesame apart when the lamp is out of use, a shunt-coil and armaturetherefor, the latter being connected to said clutch in such manner as tocause the movable carbon to advance when the armature is attracted, aretractor for the armature,

acting against the shunt-coil, a series coil, an armature therefor, anda clutchoperated thereby for holding the carbon when the armature of theseries coil is attracted, substantially as described.

4:- The combination, in an arc lamp, of a movable carbon, feedingmechanism therefor, and a shunt-coil to control said mechanism, saidcoil being connected to acontact upon the carbon-rod or carbon, wherebythe shunt-circuit is interrupted when the carbon or carbon-rod passessaid contact, substantially as described.

5. The combination, in an arc lamp, of a shunt-coil whose armature has asuitable retractor and is connected to a feeding device and when thelamp is out of use is retracted to hold the carbons apart, a feedingdevice, a series coil whose armature is connected to said feeding deviceand which is normally retracted to allow the carbon to approach, wherebya current passing through the lamp attracts the shunt-coil armature toapproach the carbons and close the circuit through the carbons,substantially as described.

This specification signed and witnessed this 24th day of July, 1891.

SAMUEL W. RUSHMORE.

Witnesses:

CHARLES M. CATLIN, J. A. YOUNG.

